import React, {Component} from 'react'
import './game.css'

/*class Square extends Component {
 constructor() {
 super();
 this.state = {
 value: null
 }
 }

 render() {
 return (
 <button className="square" onClick={() => this.props.onClick()}>
 {this.props.value}
 </button>
 )
 }
 }*/
/**
 * 函数式组件
 * @param props
 * @returns {XML}
 * @constructor
 */
function Square(props) {
    return (
        <button className="square" onClick={props.onClick}>
            {props.value}
        </button>
    )
}

class Board extends Component {
    /* constructor() {
         super();
         this.state = {
             squares: Array(9).fill(null),
             xIsNext: true
         }
     }*/

    /*  handleClick(i) {
          const squares = this.state.squares.slice();
          if(calculateWinner(squares) || squares[i]){
              return;
          }
          squares[i] = this.state.xIsNext ? 'x' : 'o';
          this.setState(
              {
                  squares: squares,
                  xIsNext: !this.state.xIsNext
              }
          )
      }*/

    renderSquare(i) {
        return (
            <Square
                value={this.props.squares[i]}
                onClick={() => this.props.onClick(i)}
            />
        );
    }

    render() {
        /*const winner = calculateWinner(this.state.squares);
        let status;
        if (winner) {
            status = 'Winner:' + winner;
        } else {
            status = 'Next player ' + (this.state.xIsNext ? 'x' : 'o');
        }*/
        return (
            <div>
                {/*<div className="status">{status}</div>*/}
                <div className="board-row">
                    {this.renderSquare(0)}
                    {this.renderSquare(1)}
                    {this.renderSquare(2)}
                </div>
                <div className="board-row">
                    {this.renderSquare(3)}
                    {this.renderSquare(4)}
                    {this.renderSquare(5)}
                </div>
                <div className="board-row">
                    {this.renderSquare(6)}
                    {this.renderSquare(7)}
                    {this.renderSquare(8)}
                </div>
            </div>
        )
    }
}

class Game extends Component {
    constructor() {
        super();
        this.state = {
            history: [{
                squares: Array(9).fill(null)
            }],
            xIsNext: true,
            stepNumber: 0
        }
    }

    handleClick(i) {
        const history = this.state.history.slice(0, this.state.stepNumber + 1);
        const current = history[history.length - 1];
        const squares = current.squares.slice();
        if (calculateWinner(squares) || squares[i]) {
            return;
        }
        squares[i] = this.state.xIsNext ? 'x' : 'o';
        this.setState({
            history: history.concat([{
                squares: squares
            }]),
            xIsNext: !this.state.xIsNext,
            stepNumber: history.length
        })
    }

    jumpTo(step) {
        this.setState({
            stepNumber: step,
            xIsNext: (step % 2) ? false : true
        })
    }

    render() {
        const history = this.state.history;
        const current = history[this.state.stepNumber];
        const winner = calculateWinner(current.squares);
        //历史记录，退回
        const moves = history.map((step, move) => {
            const desc = move ?
                'move #' + move :
                'Game start';
            return (
                <li key={move}>
                    <a href="#" onClick={() => this.jumpTo(move)}>
                        {desc}
                    </a>
                </li>
            )
        })
        let status;
        if (winner) {
            status = 'Winner:' + winner;
        } else {
            status = 'Next player:' + (this.state.xIsNext ? 'x' : 'o');
        }
        return (
            <div className="game">
                <div className="game-board">
                    <Board
                        squares={current.squares}
                        onClick={(i) => this.handleClick(i)}
                    />
                </div>
                <div className="game-info">
                    <div>{status}</div>
                    <ol>{moves}</ol>
                </div>
            </div>
        )
    }
}

function calculateWinner(squares) {
    const lines = [
        [0, 1, 2],
        [3, 4, 5],
        [6, 7, 8],
        [0, 3, 6],
        [1, 4, 7],
        [2, 5, 8],
        [0, 4, 8],
        [2, 4, 6],
    ];
    for (let i = 0; i < lines.length; i++) {
        const [a, b, c] = lines[i];
        if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
            return squares[a];
        }
    }
    return null;
}

export default Game